Sample injection means

ABSTRACT

A sample injection device is provided, comprising a vented needle having a body, the body having an upper end and a lower end, a point on the lower end, an injection passageway running axially through the body and communicating between the upper end and the lower end, and a vent passageway, running through the body and communicating between the lower end and the exterior of the body. The upper end of the body is connectable to a valve, and the lower end is connectable to a receptacle for receiving samples.

RELATED APPLICATIONS

This is a continuation-in-part application of U.S. patent applicationSer. No. 720,166, filed 4-5-85 now U.S. Pat. No. 4,651,574 by theinventor herein and entitled "Sample Injection Means", specific mentionbeing made to obtain the benefit of the prior application's filing date.

BACKGROUND OF INVENTION

1. Field of Invention

This invention relates to sampling devices and, more particularly, todevices which receive samples from a flowing fluid line, such as aprocess line.

2. Description of Prior Art

In many processes, such as those involved in manufacturing andindustrial operations, it is imperative that samples be taken from linesof flowing fluid. It is desirable that such samples be taken so as toavoid contamination of the sample, as well as to avoid contamination ofthe surrounding environment. Since a minimal disturbance of the processflow is also desirable, the sample is usually taken under pressure bytapping a conduit containing the flowing medium to be sampled. This isaccomplished by tapping the process line with a sample line andproviding a valve which can be opened to allow a sample of the fluid toescape into a sample receptacle. Because of the hazardous nature of manyprocess fluids, it is desirable that human contact with the sample beminimized.

Examples of patented sampling devices may be seen by examining thefollowing patents, which are incorporated herein by reference:

U.S. Pat. No. 2,844,964 (Guibert)

U.S. Pat. No. 2,693,705 (Casler)

U.S. Pat. No. 3,276,265 (Taft)

U.S. Pat. No. 3,383,923 (Conche, et al)

U.S. Pat. No. 3,872,730 (Ringrose)

U.S. Pat. No. 4,014,216 (Thorton, et al)

U.S. Pat. No. 4,118,987 (Zeh)

U.S. Pat. No. 4,174,632 (Jansen)

U.S. Pat. No. 4,380,176 (Bauer, et al)

U.S.S.R. patent No. 549,706

From an examination of the above listed patents, it will become apparentthat it is generally known to provide a sampling mechanism wherebysample fluid from a valve passes through a hollow needle, which isinserted through a septum in a removable sample container, thus fillingthe container. Because a substantial seal is created between the septumand the needle, a vent must be provided in the sample container in orderfor fluid under pressure to safely enter the container. In Jansen andZeh, listed above, the vent is provided by a second needle.

The two needle approach described above has proven to be unsatisfactory.By puncturing the septum twice, there is a greater possibility ofleakage should the sample container be over-filled. Substances, such ashazardous acids, etc., would then contaminate and possibily damageprocess equipment, pollute the environment and possibly injure thepersonnel involved in collecting the sample. Also, the needles disclosedin the prior art are beveled so as to produce a sharp edge which cuts asit penetrates a septum. This cutting action results in a poor sealbetween the needle and the septum, further resulting in an increasedprobability of leakage.

Also, the presence of two needles has created the problem of multiplepunctures in the septum as a sample container is repeatedly removed andthen re-installed. Looking at the Zeh patent, for example, if the samplecontainer were rotated slightly and then re-installed, the needles wouldpierce the septum at different points, resulting in leakage through theoriginal puncture holes in the septum. The Jansen device attempted tosolve this problem by providing side-by-side needles which are centeredso as to pierce the septum in the same place, regardless of therotational position of the sample container. This arrrangement has alsoproven unsatisfactory, in that an inadequate seal is formed when the twoneedles are reinserted into the same puncture hole.

SUMMARY OF THE INVENTION

Accordingly, it is an object of this invention to provide a sampleinjection means which minimizes sample leakage while allowing adequateventing of the sample container.

It is another object of this invention to provide a sample injectionmeans which penetrates a septum with a single needle, and whichminimizes the cutting of the septum.

Therefore, a sample injection means is provided, comprising a ventedneedle having a body, the body having an upper end and a lower end, apoint on the lower end, an injection passageway running axially throughthe body and communicating between the upper end and the lower end, anda vent passageway, running through the body and communicating betweenthe lower end and the exterior of the body. The upper end of the body isconnectible to a valve and the lower end is connectible to a receptaclefor receiving samples.

The above and other objectives and advantages of the invention willbecome apparent from the following description when considered with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view of a preferred embodiment of theinvention

FIG. 2 is a sectional view of a preferred embodiment of the invention.

FIG. 3 is a sectional view of a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

As shown in FIG. 1, the sample injection means 1 is connectable to aprocess line 2 by means of a sample line 3 and valve 4. A vented needle5 is connectable to the valve 4, preferably by a threaded valve fitting17.

As shown in greater detail in FIG. 2, the vented needle 5 comprises asolid body 26 having an upper end 27 and a lower end 28. A needle shaft31, preferably cylindrical, is machined onto lower end 28. At the end ofneedle shaft 31 is a point 15, which is preferably conical in shape, andpreferably forming an acute angle of 20° with the longitudinal axis ofthe needle 5. Threaded shroud fitting 18 is machined onto lower end 28for attachment to a shielding means, such as shroud 6. Injectionpassageway 13 transmits sample fluid through the needle 5. Ventpassageway 14 vents gases and excess sample fluids from sample bottle 9to vent line opening 16, to which may be attached a vent line fitting12, which, in turn, is attachable to a vent line 11. Vent line 11 maylead to a closed waste container or may be coupled with valving and apressure reducing mechanism, such as a venturi, in order to return thecontents of the vent line 11 to the process line 2. Wrench fitting 19may be machined onto needle 5 as shown, to facilitate installation.

As can be seen, point 15 will penetrate a septum 8 in opening 25 ofsample bottle cap 7. The conical shape of point 15, coupled with thelocation of the emergence of passageways 13 and 14 above the point 15,minimizes the cutting of the septum 8 which occurs with prior artdevices. It is preferable, for effective sealing, that septum 8 becomposed of chemically resistant elastomers of the chemical grouphexafluoropropylene vinylidene fluoride. Septums of natural rubber,buna-n (nitride), silicone, buna-s or neoprene are much less effective.Also, it has been found that a septum thickness of 1/8 inch ispreferable.

As a safety measure, a shroud 6 may be provided. A top opening 20 inshroud 6 receives shroud fitting 18. Shroud 6 should envelope samplebottle 9 in order to provide a maximum shield from sample spillage orbottle breakage. Bottom opening 30 in shroud 6 allows for insertion ofsample bottle 9. Shroud cavity 29 may be shaped so as to accommodatelarious sizes of sample bottles 9. However, it is preferred that cavity29 closely correspond to the external dimensions of bottle 9 so as toassure the centering of bottle 9, and thus the centering of point 15 soas to penetrate septum 8 in the same place regardless of the degree ofrotation of bottle 9. Inspection ports 21 are provided to aid inpreventing over-filling of bottle 9 while maximizing the shieldingeffect of shroud 6. Bottle handling slots 24 are provided to aid ininstallation and removal of sample bottles 9.

Shroud cap 10 provides a closure for bottom opening 30, assuring maximumsafety. Shroud cap 10 is removably attachable to shroud 6, by means oflocking pins 23 and j-slots 22.

In applications where a septum 8 is not needed or is not dictated bysafety considerations, the needle embodiment shown in FIG. 3 willprovide an efficient means for sampling, while eliminating septum 8. Ascan be seen, a resilient stopper 32 is fitted about needle shaft 31.Preferably, stopper 32 is provided with an opening 35 therein whichopening 35 is of a slightly smaller diameter than shaft 31, ensuring atight fit while enabling the easy replacement of stopper 32. Thus, asample bottle 9 (not shown entirely in FIG. 3) having mouth 33 maysimply be thrust onto stopper 32 for sampling. Upon removal, a separatestopper may be used to seal bottle 9. In such situations a threadedbottle mouth and threaded bottle cap (as shown in FIG. 1) areeliminated. Shroud 6 and shroud cap 10 may be utilized as previouslydescribed. In this embodiment, tip 34 of shaft 31 may comprise a bluntor rounded (as shown in FIG. 3) tip for safety, since it is notnecessary to puncture a septum.

Thus, as can be seen, a sample injection means 1 is provided whichaccomplishes sampling and venting with a single vented needle 5,resulting in safer, more efficient sampling. Environmental contaminationis minimized. By providing venting outside of shroud 6, contamination ofthe exterior of sample bottle 9 is also reduced. Vented needle 5 iseasily adaptable to fit many sampling devices. Applications for thedevice include the sampling of hazardous materials and known carcinogenssuch as benzene, carbon tetrachloride, sulfuric acid and the like;fuming materials, such as monochloracetic acid; and biologicalcompounds, such as gene-spliced microorganisms. While the aboveembodiments of the invention have been defined in specific terms, itwill be obvious to those skilled in the art that variation may be madewithout departing from the spirit and scope of the invention, as definedby the following claims.

I claim:
 1. A sample injection means, comprising a single vented needlehaving a unitary body, said body having an upper end and a lower end, aneedle shaft extending from said lower end, said shaft having a tipthereon, an injection passageway running axially through said body andcommunicating between the exterior of said upper end and the exterior ofsaid tip, and a vent passageway, running through said body andcommunicating between an endpoint located on the exterior of said tipand the exterior of said body above said endpoint and below the exteriorof said upper end, when in use said upper end being connected to a valveand said lower end being connected to a receptacle for receivingsamples.
 2. A sample injection means according to claim 1, furthercomprising a resilient stopper, having an opening therein of sufficientsize so as to receive said shaft, said stopper being fixedly positionedaround said shaft above said tip.
 3. A sample injection means accordingto claim 2, wherein said opening is slightly smaller than the diameterof said shaft such that said stopper fits tightly around said shaft. 4.A sample injection means according to claim 3, wherein said shroud isprovided with at least one inspection port, communicating between saidcavity and the exterior of said shroud.
 5. A sample injection meansaccording to claim 2, further comprising a sample bottle, having a mouthof a diameter less than the greater diameter of said stopper, such thatsaid stopper will provide a seal when pressed into said mouth of saidbottle.
 6. A sample injection means according to claim 2, furthercomprising a shroud cap, removably attachable to said shroud so as toclose said bottom opening of said shroud.
 7. A sample injection meansaccording to claim 1, further comprising a shroud having an interiorcavity communicating with a bottom opening, said cavity and bottomopening shroud also having a top opening communicating between theexterior of said shroud and said cavity and connectable to said lowerend of said body such that said vent passageway emerges from said bodyexterior to said shroud.
 8. A sample injection means according to claim7, further comprising a vent line connectable to said needle body so asto communicate with said vent passageway.